Metamorphic evolution of the southern part of the Hidaka belt, Hokkaido, Japan

Abstract

The Hidaka metamorphic terrane in the Meguro-Shoya area, Hokkaido, Japan is divided into four progressive metamorphic zones: A-biotite zone; B-cordierite zone; C-cordierite-K-feldspar zone; and, D-sillimanite-K-feldspar zone of the andalusite-sillimanite facies series type of metamorphism. The metamorphic grade ranges from the higher temperature part of the greenschist facies (zone A) through the amphibolite facies (zones B and C) to the lower temperature part of the granulite facies (zone D). The zone boundaries intersect the bedding planes at high angles. P-T conditions estimated are 450-550°C and 2 kbar for zone A, 550400°C and 2-2.5 kbar for zone B, 600450°C and 2.5-3 kbar for zone C and 650-750°C and 3-4 kbar for zone D. The metapelites of zone D were partially melted.At the later stage of the regional metamorphism which is early Oligocene to early Miocene in age, cordierite tonalite and biotite tonalite intrusives associated with segments of the highest grade rocks (zone D) were emplaced into the lower temperature part of the regional metamorphic rocks, giving rise to a contact metamorphic aureole. The thermally metamorphosed terrain (zone C') belongs to the arnphibolite facies and its P-T conditions are estimated to have been 550-700°C and 2 kbar.The P-T-t paths of the Hidaka metamorphism show a thickening-heating-uplifting process. The metamorphism is inferred to have taken place beneath an active island arc accompanied by partial melting of the crust. This paper first discusses the metamorphic facies and the P-T conditions of the Hidaka Key-words: andalusite-sillimanite type meta-west. morphism; Hidaka metamorphic belt; P-T-l path; orogenic belt

Petrology of a peculiar amphibolite boulder rich in deep vivid green-colored amphibole porphyroblast from Hidaka Town, Hokkaido, Japan

“…(Messiga et al, 1999) Cr 2 O 3 Cr (Me vel and Kie nast, 1986;Nishiyama et al, 1986;Ashley and Martyn, 1987;Harlow and Olds, 1987;Treloar, 1987;Gil Ibarguchi et al, 1991;Banno, 1993;Sakamoto and Takasu, 1996;1997;Maekawa et al, 2004;Tsujimori and Liou, 2004;Nagashima et al, 2006) Al 2 O 3 , CaO, ( Na 2 O) ( (Niu, 2004;Paulick et al, 2006), tremolite actinolite schists (tremolite schist) (Maekawa et al, 2004), and rodingites and their original rocks (Katoh and Niida, 1983) are also shown. Arrows indicate compositional change from the original rock to the rodingites.…”

“…(Me vel and Kie nast, 1986;Nishiyama et al, 1986;Ashley and Martyn, 1987;Harlow and Olds, 1987;Treloar, 1987;Gil Ibarguchi et al, 1991;Banno, 1993;Sakamoto and Takasu, 1996;1997;Messiga et al, 1999Maekawa et al, 2004Tsujimori and Liou, 2004;Nagashima et al, 2006) (Cannat et al, 1997Dick et al, 2003 ( Bach et al, 2004Bach et al, , 2006Paulick et al, 2006; 2008) ( ) (Mozgova et al, 1999;Kelley et al, 2001;Charlou et al, 2002;Douville et al, 2002) ( Kelley et al, 2005) ( ) (Takai et al, 2004(Takai et al, , 2006 1959;Miyashita et al, 1994;2001; 2006) ( Fig. 1) (Miyashita et al, 1994) (Hashimoto, 1975;Miyashita et al, 1994) (Hashimoto, 1975;Kagami, 1994) ( 1967;Komatsu, 1974Komatsu, , 1975Furusho and Kanagawa, 1999) ( Kiminami et al, 1985;Kiyokawa, 1992;2001; 1999) (Yagi et al, 1968;…”

Anatexis and chemical evolution of pelitic rocks during metamorphism and migmatization in the Hidaka metamorphic belt, Hokkaido.

“…The mineral assemblage of orthopyroxene + garnet + cordierite is common in zone E. Zone C' is a contact aureole around the igneous complex (Shiba, 1988). Metamor phic conditions were estimated by Osanai et al (1986) and Shiba (1988) to be 6-6.5 kb, 650 750°C in the higher grade part of zone D, and 6.5-7 kb, 750-800°C for zone E. These metamor evolution of pelitic rocks 323 BT.' phic conditions are sufficient for the pelitic gneisses to melt (e.g.…”

Notes on petrograhy and rock-forming mineralogy. (18) A corudum+spinel+chlorite pseudomorph after sapphirine from the Nikanbetsu gabbro complex in the southwestern Hidaka metamorphic belt.

“…However, the occurrence of sapphirine in Japan is only repor ted by Miyashita et al (1980) (Shiba, 1988 9: Mudstone and sandstone of the Hidaka Supergroup . 10: Saruru -Toyoni shear zone.…”